Many of my friends (some from the circle of Alex Grey, whose illustration you use on top) are into this. Myself, never having taken drugs, I am too chicken to try, but also I adhere to a principle in my art, as Dali said: "I am the Drug". I had never found it very difficult to meditate myself into a state of higher consciousness, and when I create art, the process in itself serves a gateway. In fact when my work has progressed to the point where I can see that it is near completion, I lose interest. That's one of the reasons I have so many unfinished works around. The process is the trip for me, the finish is just work.